Cats, maps and nanoflows: some recent developments in nonequilibrium nanofluidics

A review of some recent advances focusing on the problem of nano-scale fluids far from equilibrium modelled by nonequilibrium molecular dynamics (NEMD) is presented. It will be demonstrated how novel materials such as dendrimers can be successfully modelled using NEMD methods and how the distortion of their geometry by the imposed field has a significant influence on the transport properties of such fluids. Furthermore, it will be shown how a famous chaotic mapping scheme—the Arnold cat map—can be usefully employed for molecular dynamics (MD) simulations of an important industrial flow, namely elongational flow. This is the first connection ever made between the use of discrete dynamical chaotic maps and a practical application in MD simulations. It also highlights the problem that elongation is a highly unstable flow. Finally, a nonlocal constitutive model for the transport coefficients of nano-confined fluids (e.g., flows in nanoporous materials) is implemented. It is shown how such a model can be used to compute an effective shear viscosity for inhomogeneous fluids.